I had the chance of running. I didn’t win. Someone else has a better chance than I do. And that’s what we believe, and that’s why I’m not running. And you know, circumstances can change, but I’m just not going to let my head go there.”

No, no, no. Saying "circumstances can change" is what happens when you fail to slam a creaky door shut and then turn around to find it is once again wide open.

To refresh Romney's memory, here are the unwritten, but inviolable, rules for any prominent politician who wants to rule out running for president and wants the media to actually believe them.

No Hedging

This is the most basic rule. You must literally omit "ifs, ands or buts" from your response. You cannot say it depends on the other candidates running, or how you feel next year, or anything else that sounds like the verbal equivalent of a wink. "Circumstances can change" is a clear violation of this rule.

Tense Matters

Another problem with Romney's reply to Hugh Hewitt is the phrase, "I'm not running." That is the present tense. It is 2014, and the election is in 2016. No one is actually running now (except perhaps Rand Paul). And if you say,"I have no plans to run," you're deliberately playing coy. For the disavowal to mean something, you must use the future tense, as in, "I will not run for president in 2016." Sen. Elizabeth Warren has fallen into this trap before, too, but she took the novel step of putting something in writing by having her lawyers send a wrist-slapping letter to the "Ready for Warren" political action committee. Using the words "never" or "no chance" can also be helpful here.

Invoke William Tecumseh Sherman

If you really want to the queries to stop, this is the only way to go. The 1884 statement of the Civil War general has become American lore for a reason, and was most famously invoked by President Lyndon Johnson when he decided not to run for re-election in 1968. To deliver a Shermanesque statement, simply say these words: "I will not accept if nominated and will not serve if elected."